This invention relates to integrated circuits and methods of fabricating integrated circuits.
The manufacture of circuits on semiconductor wafers begins with xe2x80x9cfront endxe2x80x9d, which is the creation of circuit elements and devices like field effect transistors (FETs) and capacitors. These devices are covered by a dielectric layer and then xe2x80x9cwindowsxe2x80x9d are opened in the dielectric layer over the device contacts and extend all the way through the dielectric. The windows are filled with an electrical conductor material to create an electrically conductive via that brings the device contacts, such as to the source, gate and drain of an FET, to the surface of the dielectric. There, the vias are connected to each other at the top of the dielectric layer to connect the devices into various circuit patterns. The levels (there are usually more than one) where the interconnection of the devices occur are known as the back end. It is desirable that as many device connections be made at the front end as possible. By doing this, the number of interconnect levels required can be reduced, the area occupied by a circuit reduced, signal transit time is shortened, leakage is reduced and general circuit performance and yield is increased.
The invention includes a method for manufacturing a merged contact in a window, comprising opening a window to one of a source and a drain of a field effect transistor and to and only partially overlapping a gate electrode of the field effect transistor, and depositing an electrical conductor connecting the gate electrode with one of the source and the drain to provide a merged contact between the gate and one of the source and the drain. Also described are integrated circuit devices made thereby, such as a field effect transistor comprising a source, a gate, a gate electrode and a drain, the field effect transistor having a merged contact electrically connecting a gate electrode of the field effect transistor and one of the drain and the source of the field effect transistor.